The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Beaverton you can figure out when it's the best time to plant purple rock cress by using the USDA zone info.

Planting Calendar for Purple Rock Cress

Frost tolerance for purple rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since purple rock cress do well in cold you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant purple rock cress in Beaverton is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant purple rock cress and expect a good harvest is probably September. Any later than that and your purple rock cress may not have a chance to really do well. If you are starting your purple rock cress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Beaverton. It might get as low as 15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Beaverton and it changes from year to year. Since half of the time in Beaverton you get surprised by a frost after March 15 be ready to cover your purple rock cress if you have one of those late frosts.

USDA Zone Info for Beaverton

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Beaverton

You may be interested in your other planting guides for Beaverton.